We're going to set off at four. ✬

I watched the expedition as it set off. ✬

Are you ready to set off? ✬

Tom set off some fireworks. ✬

Tom set off at four o'clock in the morning. ✬

Tom had no idea, as he set off for the party, that he was going to meet the love of his life that night. ✬

The avalanche was set off by skiers. ✬

We'll set off at daybreak. ✬

We'll set off first thing. ✬

We'll set off first thing in the morning. ✬